Based on the experience of analyzing pointing test data from Argo Navis customers
over the years, you will not see discernible tube flexure on this model of scope.
So as others have noted, you can eliminate it from the list of possibilities.
The good news is that whatever is causing the shift will be correctable.
As the scope rises in elevation, in which direction does the spot on the primary move?
Or is it simply wandering around every which way and settling down at some random point?
Best Regards
Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
sales@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au